so how does this actually work?
Depending on your situation, I suggest putting a high quality wifi cam or webcam on your car and use a service like ugolog.com. I've caught somebody that stole the head unit out of my Acura before this way. It's great peace of mind and it's cheap, and nothing is better than sweet sweet revenge.
As for the scratch... If it's past the clear coat, you'll obviously have to touch it up. Call up your Lexus dealer and see what they say.